Can I substitute "orange oil" for "orange water" in a Moroccan cheese ball recipe?

I also would not advise that substitution. I think Merrill has the closest sub in mind with a little orange zest. But even that is not the same.

SU is right -- orange oil would not be a good substitution. You could add just a little a bit of orange zest to get a similar floral flavor.

No - orange water is really orange flower water - it is similar to rosewater, very floral but light. Orange oil is much more concentrated. Other people might have substitution suggestions that are Moroccan inspired. If it were me I would omit it altogether, or sub with half the amount of rosewater if I had it.